Question

When heated, calcium carbonate decomposes to yield calcium oxide and carbon dioxide gas via the reaction

CaCO3(s)→CaO(s)+CO2(g)

What is the mass of calcium carbonate needed to produce 77.0 L of carbon dioxide at 1 bar and 273 K?

Express your answer with the appropriate units.

Answer 1

Given:

P = 1.0 bar

= (1.0/1.01325) atm

= 0.9869 atm

V = 77.0 L

T = 273.0 K

find number of moles using:

P * V = n*R*T

0.9869 atm * 77 L = n * 0.08206 atm.L/mol.K * 273 K

n = 3.391 mol

This is mol of CO2 formed

From balanced equation,

moles of CaCO3 required = moles of CO2 formed

= 3.391 mol

Molar mass of CaCO3,

MM = 1*MM(Ca) + 1*MM(C) + 3*MM(O)

= 1*40.08 + 1*12.01 + 3*16.0

= 100.09 g/mol

mass of CaCO3,

m = number of mol * molar mass

= 3.391 mol * 100.09 g/mol

= 339 g

Answer: 339 g